1. Technical Field
The present disclosure generally relates to a force feedback device, and more particularly, to a force feedback device for generating a unidirectional impact force feedback and an interactive system.
2. Description of Related Art
The consumers' demand to the technical qualities (for example, sound, light, and interactive effect, etc) of electronic products has been increasing drastically along with the rapid development of technologies in the 3C (computer, communication, and consumer electronics) industry. For many years, the development of electronic products has been focused on the accomplishment of audio reality and video fullness, while the related techniques for realizing touch reality have not advanced very much. Most contact devices are control devices. Namely, a user input an instruction into such a contact device by touching a switch or a sensor, and when the contact device receives the instruction, it performs a predetermined action. Contrarily, there are fewer force feedback devices.
A force feedback device generates reactive forces corresponding to a virtual object in a virtual environment by using an actuator, so as to simulate the sensation of touching and impacting a real object.
There are two major types of force feedback devices. One type of force feedback devices notify or alarm the user with single- or multi-phase vibration, and the other type of force feedback devices are dynamic (force feedback) joysticks. A dynamic joystick is usually fastened on a desktop or a platform for providing an interactive “tactile scenario” to the user. However, the monotonous vibration operation of the former and the low portability of the latter do not make these force feedback devices very satisfactory.
The interaction between players and games has been greatly improved when Nintendo released the video game console Wii in 2006. The interface of Wii is changed from the simple button interface into an emulational operation interface, and a feedback device is vibrated by detecting a handheld joystick with a wireless sensor, so as to bring a real interactive sensation to the player. However, this device still cannot provide a force feedback generated and received in a real action.
A vibrotactile haptic feedback device is disclosed in U.S. Pat. No. 6,693,622, wherein a vibration effect is achieved through oscillatory striking movements. Referring to FIG. 1A, a magnet 102 is disposed on a housing 104, and a coil 106 is wrapped around the magnet 102. The magnetic force generated by the magnet 102 is adjusted by controlling the current conducted through the coil 106, so that different forces are supplied to the magnet 110a and the magnet 110b on the pivoting member 108. A vibration is produced along the axis B by the pivot 112, and the vibration magnitude is increased by increasing the weight of the mass 114.
Referring to FIG. 1B, an electromagnetically actuated vibration system is also disclosed in U.S. Pat. No. 6,693,622. In this electromagnetically actuated vibration system, a compliant member 148 is connected to a pendulum magnet 146 to form a pendulum system, and an attractive force is produced to the pendulum magnet 146 by conducting a current through the coil 144, so as to change the pendulum stiffness. A coil 154 is wrapped around a steel core 152, and a magnetic force is generated by conducting a current through the coil 154. The magnetic force attracts the pendulum magnet 146 and causes the pendulum magnet 146 to move back and forth, so as to provide a vibrating force feedback sensation.
A force feedback device is disclosed in U.S. Pat. No. 7,084,854. According to an embodiment of the present disclosure, the force feedback device is a computer mouse, wherein a compliant spring leaf is adopted for accomplishing suspension and restoration. Referring to FIG. 2A, the mouse includes an actuator 210, a top cover 214, a base 212, and a printed circuit board (PCB) 216. When the mouse is used, the actuator 210 pushes the top cover 214 so that the user who grasps the mouse can feel a force from the top cover 214, so that a force feedback sensation is provided. FIG. 2B illustrates the structure of the actuator 210. As shown in FIG. 2B, in the actuator 210 the compliant member 220 is connected to the adapter ring 222, the adapter ring 222 is connected to the magnet 224, and a gap is formed between the coil 226 and the magnet 224. A current can be conducted through the coil 226 to move the actuator 210, so as to provide a tactile sensation to the user. According to another embodiment of the present disclosure, the force feedback device can be expanded into a 2-dimensional force feedback device (as the actuators 230 and 240 in FIG. 2C), and a desired directional oscillatory vibration is provided through a phase difference between biaxial input waveforms.
Another force feedback device is disclosed in U.S. Pat. No. 7,182,691, wherein a directional oscillatory vibration is provided through a centrifugal force. As shown in FIG. 3A, this force feedback device is applied to a game controller 300 which can provide a multi-directional force feedback to the user. The game controller 300 includes two grips 310, a direction pad 320, two joysticks 330, and a plurality of buttons 340. In the present disclosure, two rotating masses are adopted for generating an inertial force. The operation principle of the force feedback device is illustrated in FIG. 3B, wherein the two eccentric masses are respectively driven by a rotating actuator, and the rotation axes of the two eccentric masses are parallel to each other. The eccentric masses respectively generate an inertial force when they rotate at a constant velocity, and a harmonic vibration force is produced by integrating these two inertial forces. By changing the phase difference between the two eccentric masses, the direction of the harmonic vibration force can be changed, so that a force feedback in different directions can be provided to the user. As shown in FIG. 3B, forces in different directions are generated along with different phase differences.
In foregoing U.S. Pat. No. 6,693,622, the force feedback device provides an oscillatory vibration sensation by using an electromagnetic actuated vibration system. In foregoing U.S. Pat. Nos. 7,084,854 and 7,182,691, even though these force feedback devices can generate a directional vibration through the phase difference between biaxial waveforms, they can only provide an oscillatory vibration but not a more complicated force feedback scenario, and besides, because these force feedback devices are designed to generate symmetrical vibration force feedback, they have very limited route designs.